diff --git a/question/format.php b/question/format.php
index 1a53ca1bbf9..fdbcc1f3a6b 100644
--- a/question/format.php
+++ b/question/format.php
@@ -307,7 +307,7 @@ class qformat_default {
                 if ($this->catfromfile) {
                     // find/create category object
                     $catpath = $question->category;
-                    $newcategory = $this->create_category_path( $catpath, '/');
+                    $newcategory = $this->create_category_path($catpath);
                     if (!empty($newcategory)) {
                         $this->category = $newcategory;
                     }
@@ -379,14 +379,12 @@ class qformat_default {
      * but if $getcontext is set then ignore the context and use selected category context.
      *
      * @param string catpath delimited category path
-     * @param string delimiter path delimiting character
      * @param int courseid course to search for categories
      * @return mixed category object or null if fails
      */
-    function create_category_path($catpath, $delimiter='/') {
+    function create_category_path($catpath) {
         global $DB;
-        $catpath = clean_param($catpath, PARAM_PATH);
-        $catnames = explode($delimiter, $catpath);
+        $catnames = $this->split_category_path($catpath);
         $parent = 0;
         $category = null;
 
@@ -396,14 +394,17 @@ class qformat_default {
             $contextid = $this->translator->string_to_context($matches[1]);
             array_shift($catnames);
         } else {
-            $contextid = FALSE;
+            $contextid = false;
         }
-        if ($this->contextfromfile && ($contextid !== FALSE)){
+
+        if ($this->contextfromfile && $contextid !== false) {
             $context = get_context_instance_by_id($contextid);
             require_capability('moodle/question:add', $context);
         } else {
             $context = get_context_instance_by_id($this->category->contextid);
         }
+
+        // Now create any categories that need to be created.
         foreach ($catnames as $catname) {
             if ($category = $DB->get_record( 'question_categories', array('name' => $catname, 'contextid' => $context->id, 'parent' => $parent))) {
                 $parent = $category->id;
@@ -698,16 +699,16 @@ class qformat_default {
             if ($this->cattofile) {
                 if ($question->category != $trackcategory) {
                     $trackcategory = $question->category;
-                    $categoryname = $this->get_category_path($trackcategory, '/', $this->contexttofile);
+                    $categoryname = $this->get_category_path($trackcategory, $this->contexttofile);
 
                     // create 'dummy' question for category export
                     $dummyquestion = new object;
                     $dummyquestion->qtype = 'category';
                     $dummyquestion->category = $categoryname;
-                    $dummyquestion->name = "switch category to $categoryname";
+                    $dummyquestion->name = 'Switch category to ' . $categoryname;
                     $dummyquestion->id = 0;
                     $dummyquestion->questiontextformat = '';
-                    $expout .= $this->writequestion( $dummyquestion ) . "\n";
+                    $expout .= $this->writequestion($dummyquestion) . "\n";
                 }
             }
 
@@ -746,34 +747,79 @@ class qformat_default {
     /**
      * get the category as a path (e.g., tom/dick/harry)
      * @param int id the id of the most nested catgory
-     * @param string delimiter the delimiter you want
      * @return string the path
      */
-    function get_category_path($id, $delimiter='/', $includecontext = true) {
+    function get_category_path($id, $includecontext = true) {
         global $DB;
-        $path = '';
-        if (!$firstcategory = $DB->get_record('question_categories',array('id' =>$id))) {
+
+        if (!$category = $DB->get_record('question_categories',array('id' =>$id))) {
             print_error('cannotfindcategory', 'error', '', $id);
         }
-        $category = $firstcategory;
         $contextstring = $this->translator->context_to_string($category->contextid);
+
+        $pathsections = array();
         do {
-            $name = $category->name;
+            $pathsections[] = $category->name;
             $id = $category->parent;
-            if (!empty($path)) {
-                $path = "{$name}{$delimiter}{$path}";
-            }
-            else {
-                $path = $name;
-            }
-        } while ($category = $DB->get_record( 'question_categories',array('id' =>$id )));
+        } while ($category = $DB->get_record( 'question_categories', array('id' => $id )));
 
         if ($includecontext){
-            $path = '$'.$contextstring.'$'."{$delimiter}{$path}";
+            $pathsections[] = '$' . $contextstring . '$';
         }
+
+        $path = $this->assemble_category_path(array_reverse($pathsections));
+
         return $path;
     }
 
+    /**
+     * Convert a list of category names, possibly preceeded by one of the
+     * context tokens like $course$, into a string representation of the
+     * category path.
+     *
+     * Names are separated by / delimiters. And /s in the name are replaced by //.
+     *
+     * To reverse the process and split the paths into names, use
+     * {@link split_category_path()}.
+     *
+     * @param array $names
+     * @return string
+     */
+    protected function assemble_category_path($names) {
+        $escapednames = array();
+        foreach ($names as $name) {
+            $escapedname = str_replace('/', '//', $name);
+            if (substr($escapedname, 0, 1) == '/') {
+                $escapedname = ' ' . $escapedname;
+            }
+            if (substr($escapedname, -1) == '/') {
+                $escapedname = $escapedname . ' ';
+            }
+            $escapednames[] = $escapedname;
+        }
+        return implode('/', $escapednames);
+    }
+
+    /**
+     * Convert a string, as returned by {@link assemble_category_path()},
+     * back into an array of category names.
+     *
+     * Each category name is cleaned by a call to clean_param(, PARAM_MULTILANG),
+     * which matches the cleaning in question/category_form.php. Not that this
+     * addslashes the names, ready for insertion into the database.
+     *
+     * @param string $path
+     * @return array of category names.
+     */
+    protected function split_category_path($path) {
+        $rawnames = preg_split('~(?<!/)/(?!/)~', $path);
+        $names = array();
+        foreach ($rawnames as $rawname) {
+            $names[] = clean_param(trim(str_replace('//', '/', $rawname)), PARAM_MULTILANG);
+        }
+        return $names;
+    }
+
     /**
      * Do an post-processing that may be required
      * @return boolean success
diff --git a/question/simpletest/testimportexport.php b/question/simpletest/testimportexport.php
new file mode 100644
index 00000000000..8a16c10f856
--- /dev/null
+++ b/question/simpletest/testimportexport.php
@@ -0,0 +1,88 @@
+<?php
+
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+
+/**
+ * Unit tests for the question import and export system.
+ *
+ * @package core
+ * @subpackage questionbank
+ * @copyright 2010 The Open University
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+require_once($CFG->libdir . '/questionlib.php');
+require_once($CFG->dirroot . '/question/format.php');
+
+
+/**
+ * Subclass to make it easier to test qformat_default.
+ *
+ * @copyright 2009 The Open University
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class testable_qformat extends qformat_default {
+    public function assemble_category_path($names) {
+        return parent::assemble_category_path($names);
+    }
+
+    public function split_category_path($names) {
+        return parent::split_category_path($names);
+    }
+}
+
+
+/**
+ * Unit tests for the matching question definition class.
+ *
+ * @copyright 2009 The Open University
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class qformat_default_test extends UnitTestCase {
+    public function test_assemble_category_path() {
+        $format = new testable_qformat();
+        $pathsections = array(
+            '$course$',
+            "Tim's questions",
+            "Tricky things like / // and so on",
+            'Category name ending in /',
+            '/ and one that starts with one',
+            '<span lang="en" class="multilang">Matematically</span> <span lang="sv" class="multilang">Matematiskt (svenska)</span>'
+        );
+        $this->assertEqual('$course$/Tim\'s questions/Tricky things like // //// and so on/Category name ending in // / // and one that starts with one/<span lang="en" class="multilang">Matematically<//span> <span lang="sv" class="multilang">Matematiskt (svenska)<//span>',
+                $format->assemble_category_path($pathsections));
+    }
+
+    public function test_split_category_path() {
+        $format = new testable_qformat();
+        $path = '$course$/Tim\'s questions/Tricky things like // //// and so on/Category name ending in // / // and one that starts with one/<span lang="en" class="multilang">Matematically<//span> <span lang="sv" class="multilang">Matematiskt (svenska)<//span>';
+        $this->assertEqual(array(
+                    '$course$',
+                    "Tim's questions",
+                    "Tricky things like / // and so on",
+                    'Category name ending in /',
+                    '/ and one that starts with one',
+                    '<span lang="en" class="multilang">Matematically</span> <span lang="sv" class="multilang">Matematiskt (svenska)</span>'
+                ), $format->split_category_path($path));
+    }
+
+    public function test_split_category_path_cleans() {
+        $format = new testable_qformat();
+        $path = '<evil>Nasty <virus //> thing<//evil>';
+        $this->assertEqual(array('Nasty  thing'), $format->split_category_path($path));
+    }
+}